Summary:
It prunes abstract memories on `assert` commands.
Problem: Since the assert command is sometimes translated to two
sequential `if` statments, it was not able to prune the memory
precisely at `assert` commands in Inferbo---the pruned memory at the
first branch was joined before the second branch.
Solution: To avoid losing the pruning information at the first branch,
now, it records which locations are pruned at the first branch and
applies the same pruning at the next branch if they have
semantically the same condition.
Reviewed By: mbouaziz
Differential Revision: D6895919
fbshipit-source-id: 15ac1cb
Summary:
Model for `folly::split` that handles the representation in the cpp model.
Depends on D6544992
Reviewed By: jvillard
Differential Revision: D6545006
fbshipit-source-id: 2b7a139
Summary:
vector::data returns a pointer to the first value of the vector.
- The size of the (array) pointer should be the same with the vector.
- The pointer should point to the same abstract value with the vector.
Reviewed By: mbouaziz
Differential Revision: D6196592
fbshipit-source-id: cc17096
Summary: This commit adds unsigned symbol for preciser analysis results with less number of uses of min/max operators.
Reviewed By: mbouaziz
Differential Revision: D6040437
fbshipit-source-id: 999ca4c
Summary:
Next step to issue deduplication: do not keep safety conditions that are subsumed by others.
Only do it if they do not have infinite bound: replacing `0 < size` by `1 < size` is ok, but replacing it by `+oo < size` is not because it looks much more like a lack of precision.
Reviewed By: skcho
Differential Revision: D5978455
fbshipit-source-id: acc2384
Summary:
A specific type of alias is added for the vector::empty() result and it is used at pruning.
Now, there are two types of aliases:
- "simple" alias: x=y
- "empty" alias: x=v.empty() and y=v.size
So, if x!=0, y is pruned by (y=0). Otherwise, i.e., x==0, y is pruned by (y>=1).
Reviewed By: mbouaziz
Differential Revision: D6004968
fbshipit-source-id: bb8d50d
Summary:
The interval bound of the abstract domain is extended.
`[min|max](int, symbol)` => `int [+|-] [min|max](int, symbol)`
As a result, `vector::empty` can be modelled to return a more precise value: `1 - min(1, size)`.
Reviewed By: mbouaziz
Differential Revision: D5899404
fbshipit-source-id: c8c3f49
Summary:
update-submodule: facebook-clang-plugins
Moving to a newer version of clang, see ffb5dd0114
Reviewed By: jvillard
Differential Revision: D5452529
fbshipit-source-id: 28bc215
Summary:
This commit avoids precision loss on pruning.
// x -> [s$1, s$2]
if(x) { ... }
// x -> ?
before: x -> [min(0, s$1), max(0, s$2)]
because two x values, [0, 0] (true case) and [s$1, s$2] (false case), were joined after the if branch.
after: x -> [s$1, s$2]
Reviewed By: mbouaziz
Differential Revision: D5431009
fbshipit-source-id: 14a9efe
Summary:
Problem: The analyzer did not know that the value of `v.size()` is an alias of `v.infer_size`, so `v.infer_size` is not pruned by the if condition. As a result it raises a false alarm.
void safe_access(std::vector<int> v) {
if (v.size() >= 10) {
v[9] = 1; // error: BUFFER_OVERRUN Offset: [9, 9] Size: [5, 5]
}
}
void call_safe_access_Good() {
std::vector<int> v(5, 0);
safe_access(v);
}
Solution: Adding alias for return value to the abstract domain.
Now Inferbo can prune `v.infer_size` because it knows that the value of `v.size()` is an alias of `v.infer_size`. There is already an alias domain in Inferbo, so we added a specific room for the retrun value.
Reviewed By: jvillard, mbouaziz
Differential Revision: D5396988
fbshipit-source-id: 4a4702c
Summary:
:
Get rid of model location in reports.
The goal is to avoid changing `issues.exp` whenever a model is updated.
Reviewed By: jvillard
Differential Revision: D5356608
fbshipit-source-id: 88ecaba
Summary:
It instantiates fields of structures when a pointer to which is given
as a function parameter, e.g., `foo(&s);`.
Reviewed By: mbouaziz, jvillard
Differential Revision: D5337645
fbshipit-source-id: c06da29
Summary: This seems to move in the right direction. Also, `const operator[]` did not do an `access_at`, which I fixed.
Reviewed By: mbouaziz
Differential Revision: D5320427
fbshipit-source-id: c31c5ea
Summary: Unknown library returns the unknown pointer as well as the top interval.
Reviewed By: mbouaziz, jvillard
Differential Revision: D5282669
fbshipit-source-id: 34c7e18
Summary:
This commit fixes a problem that the buffer overrun checker incorrectly
stops when a global variable (bottom) is involved in control flow.
In the new version, abstract memories return Top for unanalyzed abstract
variables.
Reviewed By: mbouaziz
Differential Revision: D5016447
fbshipit-source-id: 5132448
Summary:
`[a, b] < [a, _]` and `[_, a] < [b, a]` are most probably false (it comes from size < size)
Mark definitely unsatisfied conditions as B1, others as B2+
Reviewed By: KihongHeo, jvillard
Differential Revision: D4962107
fbshipit-source-id: ba8f469
Summary:
- Use Logging for logging
- Add a few extra debug (not ON by default)
- No space before colon
Depends on D4961957
Reviewed By: KihongHeo
Differential Revision: D4961989
fbshipit-source-id: 7c8697d
Summary: `bufferoverrun` is not part of `checkers` yet so bufferoverrun tests require their own Makefile
Reviewed By: jvillard
Differential Revision: D4937558
fbshipit-source-id: 20380f1
Sungkeun Cho
Mehdi Bouaziz
Martino Luca
Kihong Heo
Jules Villard